could hack
Regular verb: hack - hacked- hacked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could hack
you could hack
she could hack
we could hack
you could hack
they could hack 	I could be hacking
you could be hacking
she could be hacking
we could be hacking
you could be hacking
they could be hacking	I could have hacked
you could have hacked
she could have hacked
we could have hacked
you could have hacked
they could have hacked	I could have been hacking
you could have been hacking
she could have been hacking
we could have been hacking
you could have been hacking
they could have been hacking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't hack
you couldn't hack
she couldn't hack
we couldn't hack
you couldn't hack
they couldn't hack 	I couldn't be hacking
you couldn't be hacking
she couldn't be hacking
we couldn't be hacking
you couldn't be hacking
they couldn't be hacking	I couldn't have hacked
you couldn't have hacked
she couldn't have hacked
we couldn't have hacked
you couldn't have hacked
they couldn't have hacked	I couldn't have been hacking
you couldn't have been hacking
she couldn't have been hacking
we couldn't have been hacking
you couldn't have been hacking
they couldn't have been hacking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I hack?
could you hack?
could she hack?
could we hack?
could you hack?
could they hack? 	could I be hacking?
could you be hacking?
could she be hacking?
could we be hacking?
could you be hacking?
could they be hacking? 	could I have hacked?
could you have hacked?
could she have hacked?
could we have hacked?
could you have hacked?
could they have hacked? 	could I have been hacking?
could you have been hacking?
could she have been hacking?
could we have been hacking?
could you have been hacking?
could they have been hacking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I hack?
couldn't you hack?
couldn't she hack?
couldn't we hack?
couldn't you hack?
couldn't they hack? 	couldn't I be hacking?
couldn't you be hacking?
couldn't she be hacking?
couldn't we be hacking?
couldn't you be hacking?
couldn't they be hacking? 	couldn't I have hacked?
couldn't you have hacked?
couldn't she have hacked?
couldn't we have hacked?
couldn't you have hacked?
couldn't they have hacked? 	couldn't I have been hacking?
couldn't you have been hacking?
couldn't she have been hacking?
couldn't we have been hacking?
couldn't you have been hacking?
couldn't they have been hacking?